Nonvolatile memory element and manufacturing method thereof

Abstract

A nonvolatile memory element comprising: a first electrode 2 ; a second electrode 6 formed above the first electrode 2 ; a variable resistance film 4 formed between the first electrode 2 and the second electrode 6 , a resistance value of the variable resistance film 4 being increased or decreased by an electric pulse applied between the first and second electrodes 2, 6 ; and an interlayer dielectric film 3 provided between the first and second electrodes 2, 6 , wherein the interlayer dielectric film 3 is provided with an opening extending from a surface thereof to the first electrode 2 ; the variable resistance film 4 is formed at an inner wall face of the opening; and an interior region of the opening which is defined by the variable resistance film 4 is filled with an embedded insulating film 5.

1. A nonvolatile memory element comprising:
 a first electrode; 
 a second electrode formed above the first electrode; 
 a variable resistance film formed between the first electrode and the second electrode, a resistance value of the variable resistance film being increased or decreased by an electric pulse applied between the first and second electrodes; and 
 an interlayer dielectric film provided between the first and second electrodes, 
 wherein said interlayer dielectric film is provided with an opening extending from a surface thereof to the first electrode and having height which is not less than a thickness of the variable resistance film; 
 said variable resistance film is formed at an inner wall face and a bottom face of said opening; and 
 an interior region of said opening which is defined by the variable resistance film is filled with an embedded insulating film and said element is configured not to flow a current in a portion other than the variable resistance film, when the electric pulse is applied between said first electrode and said second electrode. 
 
     
     
       2. The nonvolatile memory element according to  claim 1 ,
 wherein a minimum film thickness of said embedded insulating film is greater than a minimum film thickness of said variable resistance film in a plan view. 
 
     
     
       3. A nonvolatile memory element comprising:
 a first electrode; 
 a second electrode formed above the first electrode; 
 a variable resistance film formed between the first electrode and the second electrode, a resistance value of the variable resistance film being increased or decreased by an electric pulse applied between the first and second electrodes; and 
 an interlayer dielectric film provided between the first and second electrodes, wherein: 
 said interlayer dielectric film is provided with an opening extending from a surface thereof to the first electrode and having height which is not less than a thickness of the variable resistance film, 
 said variable resistance film is formed at an inner wall face of said opening, 
 an interior region of said opening which is defined by the variable resistance film is filled with an embedded insulating film, 
 said element is configured not to flow a current in a portion other than the variable resistance film, when the electric pulse is applied between said first electrode and said second electrode, and 
 said opening has a cylindrical shape and a product of a diameter of an opening plane of said opening and a height of the opening is no less than 40 times a square of a film thickness of said variable resistance film. 
 
     
     
       4. A nonvolatile memory element comprising:
 a first electrode; 
 a second electrode formed above the first electrode; 
 a variable resistance film formed between the first electrode and the second electrode, a resistance value of the variable resistance film being increased or decreased by an electric pulse applied between the first and second electrodes; and 
 an interlayer dielectric film provided between the first and second electrodes, wherein: 
 said interlayer dielectric film is provided with an opening extending from a surface thereof to the first electrode and having height which is not less than a thickness of the variable resistance film, 
 said variable resistance film is formed at an inner wall face of said opening, 
 an interior region of said opening which is defined by the variable resistance film is filled with an embedded insulating film, 
 said element is configured not to flow a current in a portion other than the variable resistance film, when the electric pulse is applied between said first electrode and said second electrode, 
 said opening is groove-shaped, 
 said variable resistance film is formed at both inner wall faces of said groove-shaped opening, 
 said second electrode includes two second electrodes which contact to said first and second variable resistance films formed at said inner wall faces, respectively, and 
 the product of the width of said groove-shaped opening and the height of said groove-shaped opening is no less than 10 times the square of the film thickness of said variable resistance film. 
 
     
     
       5. A nonvolatile memory device comprising:
 a substrate; 
 a plurality of first wires formed on the substrate so as to extend in parallel with one another; 
 a plurality of second wires formed within a plane which is located above the plurality of first wires and is parallel to a main surface of said substrate, the second wires extending in parallel with one another and spatially intersecting the plurality of first wires; and 
 a plurality of memory cells arranged in a matrix pattern so as to correspond to spatial intersection points, respectively, where the first and second wires spatially intersect, 
 wherein each of the memory cells includes: 
 a first electrode that constitutes or is connected to the first wires; 
 a second electrode that is formed above the first electrode and that constitutes or is connected to the second wires; 
 a variable resistance film formed between the first electrode and the second electrode, a resistance value of the variable resistance film being increased or decreased by an electric pulse applied between the first and second electrodes; and 
 an interlayer dielectric film provided between the first and second electrodes, 
 wherein said interlayer dielectric film is provided with an opening extending from a surface thereof to the first electrode and having a height which is not less than a thickness of the variable resistance film; 
 said variable resistance film is formed at an inner wall face and a bottom face of said opening; and 
 an interior region of said opening which is defined by said variable resistance film is filled with an embedded insulating film and said element is configured not to flow a current in a portion other than the variable resistance film, when the electric pulse is applied between said first electrode and said second electrode. 
 
     
     
       6. The nonvolatile memory device according to  claim 5 ,
 wherein, in each memory cell, a diode material having a rectifying characteristic is formed at a bottom face of said opening so as to be located between said variable resistance film and the first electrode. 
 
     
     
       7. The nonvolatile memory device according to  claim 5 ,
 wherein, in each memory cell, a diode material having a rectifying characteristic is formed at a top face of said opening so as to be located between said variable resistance film and the second electrode. 
 
     
     
       8. A method of manufacturing a nonvolatile memory element, the method comprising:
 a step (a) of forming a first wire on a substrate; 
 a step (b) of forming an interlayer dielectric film configured to cover said first wire; 
 a step (c) of forming a contact hole on the first wire so as to pierce through said interlayer dielectric film; 
 a step (d) of forming a variable resistance film over exposed faces of said interlayer dielectric film and said first wire; 
 a step (e) of removing the variable resistance film formed on the exposed faces of said interlayer dielectric film so as to leave the variable resistance film formed on the inner wall face and the bottom face of the contact hole; 
 a step (f) of forming an embedded insulating film over exposed faces of said interlayer dielectric film, said first wire and said variable resistance film; 
 a step (g) of removing the embedded insulating film formed on the exposed faces so as to leave the embedded insulating film formed in an interior region of the contact hole which is defined by the variable resistance film; and 
 a step (h) of forming a second wire on the variable resistance film. 
 
     
     
       9. The method of manufacturing the nonvolatile memory element according to  claim 8 , further comprising the step (i) of forming a diode material having a rectifying characteristic between the variable resistance film and the first wire or between the variable resistance film and the second wire. 
     
     
       10. A method of manufacturing a nonvolatile memory element, the method comprising:
 a step (a) of forming a first wire on a substrate; 
 a step (b) of forming an interlayer dielectric film configured to cover said first wire; 
 a step (c) of forming a contact hole on the first wire so as to pierce through said interlayer dielectric film; 
 a step (d) of forming a variable resistance film over exposed faces of said interlayer dielectric film and said first wire; 
 a step (e) of forming an embedded insulating film over exposed faces of said interlayer dielectric film; 
 a step (f) of removing the embedded insulating film formed on the exposed faces and removing the variable resistance film formed on the exposed faces so as to leave the variable resistance film formed on an inner wall face and a bottom face of the contact hole and so as to leave the embedded insulating film formed in an interior region of the contact hole which is defined by the variable resistance film; and 
 a step (g) of forming a second wire on the variable resistance film. 
 
     
     
       11. A method of manufacturing a nonvolatile memory element, the method comprising:
 a step (a) of forming a first wire on a substrate; 
 a step (b) of forming an interlayer dielectric film configured to cover said first wire; 
 a step (c) of forming a groove-shaped opening on the first wire so as to pierce through said interlayer dielectric film; 
 a step (d) of forming a variable resistance film over exposed faces of said interlayer dielectric film and said first wire; 
 a step (e) of removing the variable resistance film formed on the exposed faces so as to leave the variable resistance film formed on both inner wall faces of said opening; 
 a step (f) of forming an embedded insulating film over exposed faces of said interlayer dielectric film, said first wire and said variable resistance film; 
 a step (g) of removing the embedded insulating film formed on the exposed faces so as to leave the embedded insulating film formed in an interior region of the contact hole which is defined by the variable resistance film; and 
 a step (h) of forming a second wire on the variable resistance film.